Cementation process.



No. 872,755. PATENTED DEC. 3, 1907.

M. RUTHENBURG.

GBMBNTATION PROCESS.

APPLICATION IILBD JAN.17. 1906.

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'M.`RUTHENBURG.

GB-MENTTION PROCESS.

APPLICATION FILED JAN.17, 1906.

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. plates. Fig. Il, shows the application of my MARCUS RUTHENBURG, OF LOGKPORT, NEW YORK.

CEMENTATION PROCESS.

Specification of Letters Patent'.

Patented Dec. 3, 1907.

Application filed January 17. 1906. Serial No. 296.452.

To all 'whom it may concern.'

Beit known that l, MARCUS RUTHENBURG, of Lockport, in the county of Niagara and l State of New York, have invented certain new and useful Improvements in Cementation Processes, whereof the following is a specification, reference being had to the ac- My improvements relate to the application of an electric current to effect the car burization of cast steel or wrought iron or steel. i

As hereinafter described, the carburizing l material, for instance comminuted charcoal, l is heated in contact with the metal to be carburized, by limiting the electric current to a path parallel with the face of the metal to be carburized, by a poor conductor either comprised in the carburizing material or embedded in 'insulating material, for instance sand, which will transmit heat to the carburizing material.

I am aware that it has been proposed to `carburize an iron or steel plate by an electric current, passing through that face ofthe platewhich is to be carburized, and forming an arc adjacent thereto. Therefore, it may be observed that it is characteristic of the present invention that the carburization is l effected by an electric current which is excluded from the metal to be carburized.

My improved process is advantageous ii that not only the electric current but the heat thereby generated are localized inthe region Where required, and the temperature throughout any desired area.

In the accompanying drawings, Figure l, shows the application of my invention in its simple form to carburize two steel armor invention in a more complex form to carburize threeI steel armor plates. Fig. lll, is a 'diagram showing a convenient arrange? ment of the carbon resister. Fig. lV, shows the application of my invention to a series of car wheels.

ltoferring to Fig. I; the steel plates l, and 2, have layers of carburizing material 3, for instance, comminuted charcoal, in contact with their surfaces which are to be carbupoor conductor or resister mrterial, extends between. said layers 3, a..l is connected by the leads 5, and 6, with the op a source of current, so that said layers 3, are

raised to the proper temperature to e'iiect the carburization of the contiguous surfaces of said plates by heat transmitted from said layer 4..

Referring to Fig. Il; the steel plates 8, 9, and 10, have layers of carburizing material 12, in contact with their surfaces which are to be carburized, and distinct layers of resister material 14.eXtend between said layers l2, and are connected by the leads 16,

, and 17, with the opposite poles of source of current so that the layers 14, are heated and transmit the required heat to the layers 12.

Although l have indicated the resister material 14, as of granular form, it is to be understood that it may comprise rods or bars of suitable material, for instance, carbon, so connected as to form a continuous path for the current. Such' an arrangement is shown in Fig. Ill, wherein the carbon rods 20, are alternately connected in pairs at their opposite ends, com-*eniently by bronze metal couplings 21, and, the terminal bars are connected by the leads 23, and 124, u ith the op posite poles of a source of current. Said couplings 2l, may be hollow to receive a cooling medium directed therethrough by pipes 26, and 27. i

It is to be understood that the continuous path of resister material shown in Fig. Ill, may be directly embcddedin a layer of carburizing material or may be embedded in a layer of insulating material, for instance, sand, capable of distributing heat uniformly to the carburizing material.

Referring to Fig. 1V, a series .of cast steel car wheelsBO, are stacked one upon another and the interstices between them packed with iron oXid 3l. lt being desired to carburize only the tires or rims of said wheels, the latter are surrounded by earburizing material 32, for instance, comminuted charcoal', and said material is backed by a layer 34, comprising a resister connecting at its opposite ends with the annular conductors 35, and 36, which are respectively connected by the leads 37, and 3S, with the opposite poles of a source of current. l iind 1t convenient to assemble the wheels 30, as described, in a soaking pit, comprising the .walls 40, shown in Fig. IV.

It is to be understood that the layer 34, shown in Fig. lV, may comprise a series of posite polcs'of l connected carbon rods, embedded in commi- 7or arrangement above described, as it is obf vious that various modifications may be made therein without departing from/the essential features of my process.

1. The process of carburizing steel or iron,

which consists in heating the carburizing material in contact With the metal to be carburized, by anelectric current limited to a path extending parallel with the face of the metal to be carburized-and excluded from the latter, substantially asset forth.

2. The processfof carburizing steel or iron, Which consists in heating the carburizing ma terial inicpnta'ct With the metal to be carburized, by an electric current limited to a continuous path through a poor conductor and .excluded from the metal to be carburized, substantially as set forth.

3. rhe process-of carburizing steel or iron, which consists in heating the carburizing material in contact With the metal to be carburized, by an electric current limited to a path through the carburizing material, and

excluded from the metal to be carburized, j

substantially as set forth.

4. The process of carburizing steel or iron, Which consists in heating the carburizing material in contact With the metal to be carburized, by an electric continuous path through a poor conductor eXtendin parallel with the face of the metal to be car urized and excluded from tl1e=lat ter, substantially asset forth.

5. The process of carburizing steel or iron, y

Which consists in heating the carburizing material 1n contact with the metal to be carcurrent limited to a f l burized, by an electric current limited to a l continuous path through a poor conductor I extendlng parallel with the face of the metal j to be carburized, and maintaining said poor l conductor insulated from the carburizing ma l terial, substantially as set forth.

l 6. The process of carburizing steel or iron, l Which consists in heating the carburizing material in operative relation with the metal to l be carburized, by the action of an electric current excluded from said metal in a continuous path formed by a poor' conductor, substantially as set forth.

7. The process of carburizing steel or iron, Which consists in heating the carburizing material in operative relation with the metal to be carburized, by an electric current in a path, formed by a poor conductor, While maintaining electrical insulating heat transmitting material between said poor conductor. and said carburizing material, substantially as set forth. f

8. The process ofhardening steel or iron, which consists in maintaining carburizing material in contact with said metal backing said material with a layer of resister; and, maintaining the carburizing material at the proper temperature by lincluding said resister in an electric circuit, substantially as set forth.

` steel car Wheels, which consists in surround ving the rims of aseries of said Wheelswith a carburizing material; backing said material with a layer of resister; and, maintaining the carburizing material at the proper temperature by including said resister in an electric circuit, substantially as set forth. y In testimony whereof, l have hereunto signed my name at Lockport in the county of Niagara and State of New York, this 15th day of January, 1906.

MARCUS RUTHENBURG. fi tnesses PAUL P. PLAs'rER,

l MARK J. TOVELL.

v9. The process of hardening the rims of. 

